The objective of the current study was to evaluate the regional and voxel-wise correlation between dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) measurement of cerebral blood flow (CBF) in patients with brain tumors. Thirty patients with histologically verified brain tumors were evaluated in the current study. DSC-MRI was performed by first using a preload dose of gadolinium contrast, then collecting a dynamic image acquisition during a bolus of contrast, followed by posthoc contrast agent leakage correction. Pseudocontinuous ASL was collected using 30 pairs of tag and control acquisition using a 3-dimensional gradient-echo spin-echo (GRASE) acquisition. All images were registered to a high-resolution anatomical atlas. Average CBF measurements within regions of contrast-enhancement and T2 hyperintensity were evaluated between the two modalities. Additionally, voxel-wise correlation between CBF measurements obtained with DSC and ASL were assessed. Results demonstrated a positive linear correlation between DSC and ASL measurements of CBF when regional average values were compared; however, a statistically significant voxel-wise correlation was only observed in around 30-40% of patients. These results suggest DSC and ASL may provide regionally similar, but spatially different measurements of CBF.
The etiology of Kienböck disease, or avascular necrosis of the lunate, is controversial, and there are a myriad of treatments aimed at correcting the various hypothesized pathologies. Interventions to reduce mechanical stress on the lunate have been used for decades, including radial osteotomy with or without radial shortening, ulnar lengthening and metaphyseal core decompression procedures. However, these procedures require preservation of lunate architecture. Newer procedures to revascularize the lunate bone have emerged in the last 10 years, such as pedicled corticoperiosteal vascularized bone grafting. Once there is collapse of the radiocarpal joint or midcarpal arthrosis, the conventional treatments have included proximal row carpectomy and complete or partial wrist joint arthrodesis. Newer salvage procedures such as lunate excision with autologous or synthetic interposition grafts are now being used when possible. As this disease is relatively rare, radiologists may not be familiar with the expected post-operative radiologic findings and complications, especially of the newer treatments. The goals of this paper are to review the available treatment options and their expected appearance on postoperative imaging, with discussion of possible complications when appropriate.
In all four cases, MRA was an effective tool for displaying arterial and venous anatomy, localizing the ACF, and planning subsequent SSAE. MRA influenced management in two out of 4 patients by demonstrating bilateral feeding vessels to their ACFs that required bilateral SSAE.
Background
Patients with pancreatic cancer often lose weight during chemotherapy with associated changes in body composition. The goal of the present analysis was to describe changes in body composition in pancreatic cancer patients on an exercise regimen. The long‐term goal is to determine whether an exercise intervention may attenuate changes in body composition and function.
Methods
Twenty‐two pancreatic cancer patients of all stages who were to receive chemotherapy were recruited into a pre‐post exercise intervention study. A standard exercise prescription was individualized to include aerobic, resistance, stretch, and balance exercises. Pre‐ and post‐intervention computed tomography‐derived measures of body composition [skeletal muscle index (SMI), skeletal muscle density, visceral fat area, and subcutaneous fat area] and physical function measures (grip strength, timed up and go, 30‐s chair stand, and tandem balance stand) were evaluated using paired t‐tests, χ2 tests, and Pearson correlation coefficients.
Results
The subjects were, on average, 62 years of age, 55% were female, 95% non‐Hispanic White, and 45% were Stage IV. Body composition changes included a median 4.6% decrease in SMI (P = 0.04), 7.91% increase in skeletal muscle density (P = 0.05), 25.07% decrease in visceral fat area (P = 0.0001), and 22.08% decrease in subcutaneous fat area (P = 0.001). Adherence to aerobic and strength exercise was 65% and 57%, respectively. Some physical function measures improved, though not significantly: chair stands increased from a mean of 11.5 to 13.0 (P = 0.59) and timed up and go improved from a mean of 11.7 to 10.3 (P = 0.26). Change in right hand grip strength was marginally positively associated with changes in SMI (r = 0.53, P = 0.06). Improvements in skeletal muscle density were seen in 63% of patients, including Stage IV patients but did not correlate with change in function.
Conclusions
Exercise is feasible during neoadjuvant chemotherapy for pancreatic cancer patients of all stages and may assist with maintaining physical function and improving body composition. Further research is needed.
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